HISTORY

FM TOWNS is a personal computer released by Fujitsu Japan. They are
sold only in Japan. The first model was released at Feb. 1989, and the
last model was released at Jul., 1997. The computer is a 386-based archtecture,
but is INCOMPATIBLE with IBM-PC architecture. They are mainly used in
home, and in schools. The specifications --- improved garaphics and sounds,
built-in bootable CD-ROM drive, and 386 DOS Extender causes impressive
games and creative tools. The specifications are especially suitable for
porting AMIGA/PC-VGA games into Japanese. Around 500 thousands sets of
the computer were sold in japan.

BASIC SPECIFICATIONS

CPU:

intel i386SX or higher

memory:

1 megabyte or more, most of Towns games requiring 2 megabytes memory.

graphics:

640x480 at 256 of 16M colors, 640x480 at 16 of 4096 colors,
and 320x240 at 32768 colors screens are primarily used.

HISTORICAL BACKGROUNDS

In 1981, IBM released IBM PC. The computer had widely spread in offices.
However, the architecture was not popular in Japanese offices.
Japanese language uses Kanji letters, which requires at least 12x12 pixels area for displaying a letter.
PC's CGA is too poor to handle Japanese.
To handle Japanese language sufficiently, Japanese computer companies were developped other x86-based computers having 640x400 video adapters.
NEC's PC-9801 archtecture, which was released at 1982, was the most poplular one.
In late 1980's, at least 70% of the 16/32 bit computers are PC-9801 computers.
They were spread in home, and a number of games were released for this architecture.

The PC-9801 computers were wide-spread, however, they have poor graphics (640x400 at 16 of 4096 colors)
and sounds (4-operator/3 voice monoral FM sounds).
Therefore, like as AMIGA in US, a computer having improved graphics and sounds was considered to overcome the PC-9801 in the
home-use field.
For example, SHARP's X68000 computers, released at Mar., 1987, became popular among people who like action/shooting games.

Fujitsu, which had been released a best-seller 8-bit home computer "FM-7"
in early 1980's, was decided to release a new home computer. After FM-7
was overcome by NEC's PC-8801 computer, Fujitsu got a useful experience
that the number of usable softawre packages are important to sell computers.
Therefore, in order to acquire usable software immediately, the archtecture
of the new computer is set to be based on Fujitsu's "FMR50" architecture.
The FMR50 architecture, released at 1986, is another x86/DOS-based computer
having a constitution similar to NEC's PC-9801. The computers were sold
in moderately in Japanese office, especially in Japanese goverment office.
There have released hundreds of software packages for FMR, including Lotus
1-2-3, Wordstar, Multiplan, and dBASE III.

WHERE THE NAMES 'FM' & 'TOWNS' COME FROM ?

Many people who natively use European languages may have a question "Why
the name of the computer is plural-form, although the name defines a single
computer?". The reason will be described hereinafter.

In those days, Fujitsu provided a codename named after nobel-prized scientist
for each PC products. The codename of the first model of FM TOWNS is "Townes",
named after Charles Hard Townes (1964, phisics), an inventor of maser.
The product name came from the codename, but the word "TOWNES"
can be pronounced as Tau-Ness. Accordingly, to be pronounced as "Townz",
the letter "e" was removed from the codename.

The word "FM" is an acronym from "Fujitsu Micro".

IMPRESSIVE SPECIFICATIONS

Bootable CD-ROM drive

All models of FM TOWNS have built-in CD-ROM drives.
To boot a system from CD-ROM disk, FM TOWNS has a "hidden C:" ROM drive.
The C: drive of FM TOWNS is a ROM drive, in which a minimum MS-DOS system, CD-ROM driver and MSCDEX.EXE are installed.
This minimal DOS system works first, and the DOS system reads and executes TownsOS IPL stored in CD-ROM disk then.
The TownsOS CD-ROM disk has the IPL, MS-DOS system(IO.SYS), DOS extender, and Towns API (TBIOS).

It should be strongly insisted that Fujitsu allowed the software developers to record minimum TownsOS system in their CD-ROM
with very low license fee.
Accordingly, the software developers could sell their software recordeded in bootable CD-ROM disk.
The FM Towns users can play CD-ROM-based games without any boot diskette, even if they have no hard disk drives.

32bit based system

If you are/were a 16bit DOS programmer, you would remember 64-kilobyte segment nightmare.
Since the processor only can access 64 kilobytes of memories linearly,
it is difficult to handle a large size of data such as a graphic data or PCM sound data.

Graphics

FM TOWNS TBIOS supports so many graphics modes. Following table shows the specification of each graphic mode.

mode #

vertual screen size

displaying screen size

colors

HSYNC

mode # of overlappable screen

1

640x819

640x400

16/4096

24 kHz

1, 2

2

640x819

640x200

16/4096

24 kHz

1, 2

3

1024x512

640x480

16/4096

31 kHz

3, 5, 10

4

1024x512

640x400

16/4096

24 kHz

4, 6

5

256x512

256x256

32768

31 kHz

3, 5, 10

6

256x512

256x256

32768

24 kHz

4, 6

7

256x512

256x240

32768

15 kHz(interlace)

7, 9

8

256x512

256x240

32768

15 kHz

8, 11

9

512x256

360x240

32768

15 kHz(interlace)

7, 9

10

512x256

320x240

32768

31 kHz

3, 5, 10

11

512x256

320x240

32768

15 kHz

8, 11

12

1024x512

640x480

256/16M

31 kHz

none

13

1024x512

640x400

256/16M

24 kHz

none

14

1024x512

720x480

256/16M

15 kHz(interlace)

none

15

512x512

320x480

32768

31 kHz

none

16

512x512

320x480

32768

15 kHz(interlace)

none

17

512x512

512x480

32768

31 kHz

none

18

512x512

512x480

32768

15 kHz(interlace)

none

As shown in the above table, FM TOWNS can overlap 640x480/16 screen on 320x240/32768 screen.
It is extremely suitable for porting AMIGA/PC games with Japanese translation.
That is, 320x240/32768 screen is used for displaying high-color graphics,
that may be equivalent to VGA 320x200/256 or AMIGA 320x200/4096 screen,
while the overlapped 640x480 screen is used for displaying Japanese text,
which is not requires so many colors but requires higher resolution.

The overlapping feature is further used for a sprite function (one 256x240 screen are used for displaying sprites, and other one screen serves as a background screen), which is suitable for creating action/shooting
games, even if the function is poorer than that of X68000.